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###### tags: `Leetcode`
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# Leetcode 2414. Length of the Longest Alphabetical Continuous Substring

[link](https://leetcode.com/problems/length-of-the-longest-alphabetical-continuous-substring/)

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An alphabetical continuous string is a string consisting of consecutive letters in the alphabet. In other words, it is any substring of the string `"abcdefghijklmnopqrstuvwxyz"`.

- For example, `"abc"` is an alphabetical continuous string, while `"acb"` and `"za"` are not.

Given a string `s` consisting of lowercase letters only, return the length of the longest alphabetical continuous substring.

#### Example 1:

Input: s = "abacaba"
Output: 2
Explanation: There are 4 distinct continuous substrings: "a", "b", "c" and "ab".
"ab" is the longest continuous substring.

#### Example 2:

Input: s = "abcde"
Output: 5
Explanation: "abcde" is the longest continuous substring.

#### Constraints:

- 1 <= s.length <= 105
- s consists of only English lowercase letters.

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Using two pointers to iterate each slice of the given string, if the slice is consecutive, store the length of that slice and return the maximum.

#### Solution 1

class Solution:
    def longestContinuousSubstring(self, s: str) -> int:
        alphabet = "abcdefghijklmnopqrstuvwxyz"
        ans = 1
        l = 0
        r = l + 1
        while l < len(s) - 1:
            while s[l:r+1] in alphabet and r < len(s):
                count = r - l + 1
                ans = max(count, ans)
                r += 1
            l = r
            r = l + 1

        return ans

O(T): O(N)
O(S): O(1)

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We can iterate the given string from length 1 to len(s). By checking whether the slice is consecutive, store the maximum length of that consecutive substring.

#### Solution 2

class Solution:
    def longestContinuousSubstring(self, s: str) -> int:
        start = maxLen = 0
        for i in range(1, len(s) + 1):
            if s[start:i] in alphabet:
                maxLen = max(maxLen, i - start)
            else:
                start = i - 1

        return maxLen
        

O(T): O(N)
O(S): O(1)